No matter how frequently＿＿ the works of Beethoven still attract people all over the world.

问题补充：

No matter how frequently＿＿，the works of Beethoven still attract people all over the world.

A. performed

B. performing

C. to be performed

D. being performed

答案：

(答案→)A. performed

B. performing

C. to be performed

D. being performed

解析：考查状语从句的省略。句意：“无论贝多芬的作品多么频繁地被演奏，它们仍然吸引全世界的人们。”状语从句省略了they are.所以贝多芬的作品是被演奏，应该选过去分词。当状语从句的主语和主句的主语一致并含有系动词be时，可以省略主语和系动词be.选A。